Laminated finned cylinder



19, 1944. I l v. R. ARAMs l 2,365,152

' f LMINATED FINNED CYLINDER V l -Fi1e1Feb. 23, 1943 Vif: fr R'. Abram-L5 Patented Dec. 19, 1944 UNITED STATES PATENT OFFICE LAMINATED FINNED CYLINDER Victor R. Abrams, Detroit, Mich. Application February 23, 1943, vSerial No. y476,8'16 7 Claims. (Cl. 257-261) (Granted under the act o! March 3*, 1883, as amended April 30, 1928; 370 0. G. 757) der of an internal combustion engine, of acompressor or of aRoots blower. Another application of the invention is a conduit for the ow of fluid such `as a refrigerant. y

'I'he structure consists of a nested arrangement of tapered or conical members, each having an outwardly extending radiating n. The -inner edges or smaller ends of the tapered members 1 form a jagged wall. When the structure is to be used as a power cylinder, the wall is machined to a smooth nish. 'I'he angle of taper is such that the wall of the structure in any transverse plane consists of several thicknesses of nested members after machining. I'he chamber may be a simple cylinder or a pair of joined cylinders as in a Roots blower. A multiple of cylinders may be provided in a single structure, in which'case each of the nested members is formed with a corresponding number of tapered portions.

In a further embodiment of the invention the tapered portionsare. corrugated lengthwise, and successive members are iltted into one another at the corrugations. Several advantages-result from such an arrangement. The corrugations provide increased bonding area between successive members, increased `radiation area, and .ln-

creased structural strength. Further, the outwarding extending fins may be corrugated radially or circumferentially for increased radiation area and resistance to exing.

The invention .is fully disclosed by wayl of example in the following description andlin the accompanying drawing in which Figure 1 is an elevation of a structure according to the invention; y

Figure 2 is a vertical section thereof, showing Each of the elements from which the structure is built up includes a tapered portion I having an outwardly extending iiange or iin 2 preferably at the larger end. In this form the element can be made` by a stamping operation. Although shown essentially in conical form, the tapered portion may consist of two conjoined cones, or may be of any other shape suitable for the purposejinder consideration. 'I'he elements are nested by inserting the tapered portions one within the other, vas illustrated in the lower portion of Figure 2. The angle of the taper is large enough so that in any given transverse plane the wall thickness is built up of several thicknesses of ma- .i

terial. Suitable ttings 3 and 4 are mounted at the ends of the series to complete the assembly. The smaller ends of the portion I form a jagged surface 5 as illustrated in Figure 2.

Obviously such a surface is not suitable for a power chamber and is therefore machined and finished to a smooth wall 8. 'I'he exposed edges of the portions appear as wavy lines 'I due to the corrugations. y

In assembling the elements, prior to machin- Ing, the.. portions I should be secured together and a bra'zing operation is suitable for this purpose, as shown in U.S. Patent 2,206,286 of July 2, 1940, in which the brazing material is melted within the chamber and permitted to iiow between the nested members. Another method is to provide the brazing material in the form of sheets between the nested members and then melt the material in a hydrogen atmosphere. The

In an apparatus where the cylinder contains a l piston I2, as in Figure fl, the piston rings I3 are of greater height than the minimum distance axially of the cylinder, between any two points of two adjacent lines, with the result that the likelihood of thevring snagging in a joint is substantially eliminated.

An important property oi the exposed joints in the inner cylinder wall is Vthat the lubricating and wearing qualities of this wall are improved by the incorporation of the brazing material therein. In this connection, 'the brazing material consists chiefly of copper and may contain a quantity of an alloying metalsuch as beryllium. The melting point of the material should obviously be sufficiently high to withstand the temperature developed within the cylinder.

Elements of the general character described may be assembled into a block having a plurality of cylinders. In such case each cylinder is formed with a corresponding number of tapered portions having a common or continuous radiation n. Also, the tapered portions may be in the form of two communicating chambers suitable for use in a gear pump or a Roots blower. The superimposed ilns in an assembly may be penetrated by a suitable number of tubes for circulation of air, water or any desired cooling agent.

1n a circulating system for refrigerant or the like, the smooth machined inner wall has the further advantage of reducing the resistance to iiow. f

Although speciiic embodiments of the invention have been illustrated and described, it will heV understood that various alterations in the details on construction may be made without departing from the scope of the invention, as indicated by .the appended-claims.

What I claim is:

1. A cylinder comprising a series of nested and mutually secured elements each including a tapered -portion and a iin extending outwardly therefrom, the nested tapered portions forming a smooth bore, the angle oi'; said portions being such thatwseveral thicknesses thereof occur in any transverse plane of the nested assembly.

2. A cylinder comprising a series of nested and mutually secured elements each including a tapered portion and -a iin extending outwardly tl. zrefrom, the nested tapered portions forming a smooth bore, said portions being corrugated lengthwise, the corrugations of each portion fitting into those of the adjacent portions.

3. A cylinder comprising a series of nested and y mutually secured elements each including a tapered `portion and aA iin extending youtwardlytherefrom, the nested tapered portions forming a smooth bore, said portions .being corrugated lengthwise, the corrugations of each portion t- Y ting into those of the adjacent portions, the angle of said portions Abeing such that several thick# lnesses thereof occur in any transverse plane of the nested assembly. l

4. A cylinder comprising a series of nested eiements each including a tapered portion and a corrugated iin extending outwardly therefrom, the nested tapered portions forming a smooth boreI said portions being corrugated lengthwise, the corrugations of each portion tting into those of the adjacent portions, and means for securing said portions together.

5. A cylinder comprising a series of nested elements each including a tapered portion and a iin extending outwardly therefrom, the nested tapered portions forming a. smooth bore, said portions loeing corrugated lengthwise, the corrugations of each portion tting into those oi the adjacent portions, and bonding material between the nested portions and substantially coextensive therewith, said material being a relatively good A conductor of heat. Y

6. A cylinder comprising a series oi' nested and mutually secured elements each including a tarpered portion and a iin extending outwardly therefrom, the nested tapered portions forming la. smooth bore, said portions being corrugated lengthwise, the corrugations of each lportion fitting into those of the adjacent portions, and a bonding material securing said portions together l y therefrom, the inner' edges of said portions being finished to form a'. smooth surface, said portions being corrugated lengthwise, the corrugations of 'each portion tting into those of the adjacent portions, and a bonding material securing said portiostogether and appearing in wavy lines at said nished surface, a piston positioned to operate along said surface, a piston ring carried by said piston, the height of said ring being sumcient to engage two 'adjacent wavy lines simultaneously.

VICTOR R. ABRAMS. 

